Sewing machine



April 25, 1933. c. w. MUELLER SEWING MACHINE Filed Nov. 19, 1930 5 Sheets-Sheet 1 ZSnnentor,

' (lttorneg' April 1933- c. w. MUELLER SEWING MACHINE Filed Nov. 19, 1930 5 Sheets-Sheet 2 (Ittorneg April 25, 1933. c w MQELLER 1,905,391

SEWING MACHINE Filed NOV. 19, 1930 5 Sheets-Sheet 3 April 25, 1933- c. w. MUELLER 1,905,391

SEWING MACHINE Filed Nov. 19, 1930 5 Sheets-Sheet 4 llll llllllil April 25, 1933. c. w. MUELLER SEWING MACHINE Filed Nov. 19, 1930 5 Sheets-Sheet 5 Patented Apr. 1933 UNITED STATES PATENT OFFICE CHARLES W. MUELLER, OF ST. LOUIS, MISSOURI, ASSIGNOR TO LEWIS INVISIBLE STITCH MACHINE COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MAINE SEWING MACHINE Application filed November 19, 1930. Serial No. 496,728.

This invention relates generally to improvements in sewing machines but more partlcularly to that type known as blind stitch sewing machines.

Heretofore in the manufacture of coats, two distinct operations have been performed by two separate blind stitch sewing machines, one consisting in uniting the canvas or interlining to the coat lapel by means of a plurality of parallel lines of blind stitches, and the other consistin in stitching padding to the canvas or inter plurality of lines of through-and-through stitches. Heretofore in order to obtain the proper roll to the lapel when stitching the canvas to the body fabric, the operator first ran a line of blind stitches along one edge of the canvas, then she pushed the canvas laterally from the other edge towards the seamed edge to cause the canvas to bow or buckle, then she ran a line of blind stitches along the unseamed edge of the canvas to unite the latter with the body fabric while maintaining the bow or buckle in the canvas, and finally she ran a plurality of spaced lines of blind stitches in the canvas to unite the canvas to the body fabric. In this manner the canvas was caused to bow upwardly between adj acent lines of stitches, and thereby cause the canvas and the body fabric forming the lapel to roll in the proper direction.

Among the several objects of my invention are to provide a blind stitch sewing machine with manually controlled means for quickly adjusting the height of the stitch forming element relative to the path of travel of the needle whereby the same sewing machine may be employed for blind stitching canvas 4 to the lapels or for stitching the coat front padding to the canvas by through-andthrough stitches, thereby eliminating the necessity of employing two separate machines for these two distinct operations, and to provide means for automatically forming outwardly bowed portions between the several lines of stitches when stitching the lapel canvas to the body fabric to thereby cause the lapel to roll.

With theseand other objects in view which will more fully appear, the nature of the inlning of coat fronts by a vention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the accompanying drawings:-

Figure 1 is a front elevation of a sewing machine constructed in accordance with my invention,

Figure 2 is a top plan view thereof,

Figure 3 is a vertical sectional View taken '60 on the line 3-3 of Figure 1,

Figure 4 is a detail bottom plan view showing a part of the driving mechanism for the ridge forming device,

Figure 5 is a bottom plan view of the work '65 support and the operating parts mounted thereon,

Figure 6 is an enlarged horizontal sectional view taken directly above the stationary presser foot,

- Figure 7 is an enlarged horizontal sectional view showing the adjustable coupling between the disc supporting shaft and the actuating means therefor,

Figure 8 is a vertical sectional view taken on the line 8-8 of Figure 6,

Figure 9 is an enlarged bottom plan view (if the stationary presser foot and top feed Figure 10 is an enlarged toptplan view of the work presenting mechanism located directly below the stationary presser foot,

Figure 11 is an enlarged vertical sectional view showing the ridge forming disc in its adjusted position relative to the path of needle movement when forming blind stitches,

Figure 12 is a similar View but showing the ridge forming disc in its adjusted position when forming through-and-through stitches,

Figure 13 is an enlarged sectional view through the adjustable coupling,

Figure 14 is a plan view of a coat front showing the lapel in its curled over position,

Figure 15 is an enlarged vertical sectional view showing the relation between the presser foot, the work clamp, the ridge forming element, and the needle when stitching the lapel canvas to the body fabric, 7

Figure 16 is an enlarged sectional View showing the lapel canvas stitched to the body stitches.

fabric and showing particularly the outwardly bowed portions of the canvas between adjacent lines of stitches, and

Figure 17 is a vertical sectional view taken 5 through the shaft and support, and showing the plates and their operating structure in elevation.

Like reference numerals designate corre sponding parts throughout the several figures of the drawings.

Referring to the accompanying drawings, I have shown my invention as applied to a blind stitch sewing machine which includes a frame comprising a base 5 from which rises a standard 6 supporting an overhanging arm 7 which in turn supports at its free end a forwardly extending needle head 8. A pair of posts 9, 9 extend upwardly from the base 5 and fixed to said posts is a pivot shaft 10 on which a work arm 11 is fulcrumed. The work support 11 is provided at its left hand end with a reduced portion 12 which is located directly under a horizontally disposed stationary presser foot 13 which is fixed to the front end of the stitching head 8.

J ournaled in the overhanging arm 7 is a main or rotary shaft 14 which through a suitable coupling (not shown) oscillates a needle shaft 15 which is journaled in the needle head 8. Fixedly attached to the forward end of the needle shaft 15 is a needle arm 16 carrying a curved needle 17. This needle oscillates in a fixed path of travel directly above an opening 18 formed in the presser foot 13. A 6-motion looper 19 coo erates with the needle 17 to form a line 0 single thread chain This looper is actuated from the needle shaft 15 by a mechanism well known in this art but which is not disclosed in the drawings. Although, I have specifically shown a non-threaded looper which cooperates with the needle, it will be understood that any other complemental stitch forming mechanism may be employed.

J ournaled in suitable bearings located on the under side of the work support 11 is an oscillatory shaft 20. The longitudinal axis of this shaft is disposed in a plane at right angles to the longitudinal axis of the needle shaft 15 and said shaft 20 is disposed directly below the path of travel of said needle 17 Fixed to the left hand end of this oscillatory shaft 20 is a ridge forming disc or element 21 which projects into the opening 18 of the presser foot to form a ridge or node of fabric and to position said ridge or node into the path of the needle.

Cooperating with the under side of the stationary presser foot to clamp the fabrics against movement and to thereby resist the penetrating stroke of the needle, is a work clamp which in this instance consists of two plates 22, 23. These clamping plates are disposed on opposite sides of the ridge forming disc 21 and are pivoted to arms 24, 24 which are in turn pivoted on a stationary pivot shaft 25 fixed to the left hand end of the work support 11. These arms 24 extend rearwardly from the pivot shaft 25 under the disc shaft 20 and thence upwardly in rear of the disc 21 and consequently the pivotal connections between the clamping plates 22 and 23 and the pivot arms 24 are located in rear of said disc. Integral with the arms 24, 24 are depending arms 26, 26, and coil springs 27, 27 respectively connect the depending arms 26 with the work support 11 and there by yieldably urge the clamping plates 22, 23 into contact with the under face of the stationary presser foot 13. The front ends of the clamping plates 22, 23 are disposed in front of the opening 18 in the presser foot whereas the rear portions of said clamping plates register with said opening. A 4-motion top feed dog-28 operates in the presser foot opening 18 in rear of the path of needle travel and cooperates during each cycle with the rear portions of the clamping plates 22,23 to feed the fabrics rearwardly when the needle has been withdrawn from the fabrics. This feed dog is given its four motions from the needle shaft 15 through a mechanism which is well known in this art but which is not illustrated in the drawings.

The ridge formin disc 21 is provided with peripheral ridge orming concentric surfaces 29 and 30 which are arranged in tandem and are of different radii and form therebetween a resultant radial shoulder 31 constituting a feeding tooth. The rear concentric surface 29 has a smaller radius than the front concentric sur face 30, and the surface 29 oscillates in an arc concentric with the disc shaft 20 and in a path below the path of travel of the needle 17, whereas the front surface 30 oscillates in an arc which is also concentric with the shaft 20 but in a path above the path of travel of the needle 17.

In order to oscillate the disc shaft 20 from the main shaft 14, and to provide means for adjusting the disc 21 whereby the surface 29 or the surface 30 may be brought into cooperation with the needle and thereby form either blind stitches or throu h-and-through stitches, I have provided the ollowing mechanism:

'Journaled in suitable bearings on the under side of the base 5 is a rock shaft 32 to the left hand end of which is fixed a rock arm 33 having a pivotal connection 34 with the lower end of a link or strap 35, the upper endof which cooperates with an eccentric 36 fixed to the main shaft 14. Fixed to the left hand end of the rock shaft 32 is a rock arm 37 and pivotally connected thereto as at 38 is the lower end of a link 39 which extends upwardly through an opening 40 in the base 5 and has its upper end pivotally connected by a pin 41 to a rock arm 42 which is jourconnected as at 44 to a rock arm 45 fixed to a sleeve 46 freely \journaled on the disc shaft 20. As thus far described, the main shaft 14 will oscillate the sleeve 46 but will not impart any movement to the disc shaft 20. A sleeve 47 is fixed to the disc shaft 20 by a set screw 48, and this sleeve is provided with an integral radial arm 49 having an integral barrel 50 at its outer end. The barrel 50 overlies a flange 51 integral with the sleeve 46, and this flange is provided with a concentric periphery 52 and with inwardly extending front and rear recesses or seats 53 and 54 which extend inwardly and radially from the surface 52. Supported in the barrel 50 is a. pin 55 which is yieldably urged inwardly b toward the shaft 20 through the medium of a coil spring 56 which is disposed within the barrel. The pin is provided on its outer end with a finger piece 57 by means of which the pin may be moved outwardly or in a direction away from the shaft 20. The inner end of the pin is adapted to engage in either of the seats 53 or 54 and to be retained therein by the coil spring 56. Thus when the coupling is effected between the driving mechanism and the shaft 20 the latter will be oscillated during each revolution of the main shaft. When the pin 56 is withdrawn from its engagement with either of the seats 53 or 54, the coupling will be broken. If the pin 56 is positioned in the rear seat 54, the disc 21 will be oscillated between the points a and b and consequently the rear ridge forming surface 29 will be moved into cooperative relation with the needle. If, however, the coupling is broken and the pin 56 is positioned in the front seat 53 the path of oscillation of the disc 21 will be between the points a and d and consequently the front ridge formingsurface 30 will be moved into cooperative relation with the needle. In this latter position of adjustment of the disc, it will be noted that the shoulder or tooth 31 will not be moved rearwardly beyond the path of needle movement, or in other words, the shoulder or tooth at its extreme end of its rearward movement will be positioned in front of the path of needle movement.

The oscillations of the disc 21 are timed with the feed dog travel whereby the feeding stroke of the dog is made simultaneously with the rearward oscillatory stroke of the ridge forming disc. The feed dog in its forward and downward movement engages the rear ends of the clamping plates 22, 23 and causes the rear ends of said plates to be swung downwardly against stops 58 mounted on the arms 24, whereby upon continued forward and downward movement of the feed dog said clamping plates are bodily lowered against the tensions of the springs 27, 27 thereby freeing clamping plates and the stationary presser foot so as to permit said fabrics to be fed by the feed dog during rearward movement'of the latter. During the upward movement of the feed dog which occurs at the rear end of,

the feed stroke'thereof, the springs 27v function to return the clamping plates to their normal positions whereby the fabrics are clamped between said patesand the presser foot on opposite sides of the ridge forming disc so asto retain the fabrics against movement due to the penetrating stroke of the needle which takes place immediately upon gompletion of the feeding stroke of the feed The work support 11 is yieldably urged upwardly toward the stationary presser foot y a spring 59 and this upward swinging movement of the work support is limited by an adjustable stop pin 60 mounted in a post 61 which rises from the base 5, the pin cooperating with a depending arm 62 rigidly connected with the work support 11.

In Figure 14 I have illustrated a coat front A which includes an outer body fabric 63 and a canvas interlining 64. A plurality of pieces 65 of cloth fabric which serve as padding for the coat front are stitched to the canvas by a plurality of lines 66 of throughand-through stitches. These pieces 65 are attached to the canvas before the canvas is stitched to either the front or body fabric. The upper left hand corner of the canvas 64 is stitched to the outer body fabric 63 by a plurality of lines 67 of single thread blind stitches. The canvas 64 between adjacent lines 67 of stitches is bowed outwardly as shown in Figure 16 which results in the upper left hand corner of the coat front rolling under to form the lapel as shown in Figure 14.

I have provided means for automatically causing the canvas to be bowed outwardly, as shown in Figure 16, luring the successive forming of the lines 67 of blind stitches.

To this end the opening 18 of the presser foot extends longitudinally of the foot from a point in front. of the path of neede travel to a point Well in rear thereof. The rear portion of this opening receives the top feed dog as previously explained. The longitudinal walls of the opening 18 are undercut as at 18*, 18 on an arc whose center 18 is located in the central general plane of the disc 21 and in a horizontal plane below the lower surface 13 of the foot. Rcmovably attached to the low surface of the foot on the left hand side of the opening 18 by screws 68 is a plate 69.- This plate extends in parallelism with the opening 18 from a point in front of the path of needle movement to a point in rear thereof and the right hand wall 70 of said plate is curved in an arc struck from -.the center 18 and therefore merges with the adj acent undercut wall 18 of the presser foot.

the fabrics from being clamped between i The upper left hand corner of the clamping plate 22 is curved as at 22* in an arc struck from the center 18 and therefore this surface 22 is a convex surface and fits the concave surface of the wall of the presser foot.

When the lapel is being blind stitched, the canvas 64 is positioned above the outer body fabric 63 as shown particularly in Figure 15. The disc shaft 20 is adjusted for blind stitching operations and consequently the rear ridge forming surface 29 of the disc 21 will be moved rearwardly from the point a to the point 6 so as to position said surface in proper relation to the needle travel whereby the needle will enter the canvas and the body fabric and emerge therefrom without going entirely through the body fabric. As a result, the disc 21 is moved rearwardly, the body fabric and the superposed canvas will be projected upwardly into the opening 18 of the presser foot, as shown in Figure 15, and due to the concaved surfaces 18, 18 and 70 said fabrics will be bowed upwardly in conformity to the outline of said surfaces. By reason of the canvas 64 being disposed above the body fabric 63, it occupies an arc of a greater radius than that occupied by the body fabric. The superposed canvas and body fabric are clamped between the depending plate 69 of the presser foot and the clamping plate 22 of the work clamp to resist the penetrating stroke of the needle 17. By employing the depending plate 69 the length of the are or curve of the canvas and body fabric between the point of needle penetration and the clamping point will be increased a distance sufficient to bring about a bowed portion in the canvas between adjacent lines 67 of the stitching, and thereby effect a roll to the canvas and consequently to the lapel of the coat front.

\Vhen padding cloth 65 is stitched to the canvas the disc 21 is adjusted so as to present the front ridge forming surface 30 to the needle whereby the latter will penetrate the padding and the canvas and emerge therefrom and consequently form a line of through-and-through stitches.

From the foregoing, it will be observed that by the use of my machine it is unnecessary to form the preliminary line of stitching and then shift the lapel canvas toward said line in order to provide an initial bow in the canvas, as has been done heretofore. By the use of my machine, parallel lines of stitches may be successively made for join ing the canvas to the body fabric and automatically throwing in a sufficient amount of the canvas between adjacent lines of stitches so as to produce outwardly bowed portions of canvas whereby the lapel will be caused to automatically curl or roll in the proper direction. WVith my machine, in order to obtain maximum outward bow of the canvas between adjacent lines of stitches, said lines of stitches should not be spaced a distance apart greater than the distance between the point of needle penetration and the lower end of the plate which depends from the left hand side of the presser foot.

From the foregoing, it will be observed that I have provided means for varying the effective height of the ridge forming element; that I have provided means for adjusting the ridge forming element about the longitudinal axis of the shaft to thereby vary the effective height of said element; that I have provided means for oscillating the shaft which includes a radially adjustable connection with the shaft whereby the eflective height of the ridge forming element may be varied; that the ridge forming element is provided with concentric surfaces of different radii and arranged in tandem, and that I have provided means for increasing the length of the are assumed by the fabrics when projected into needle penetrating position whereby the upper fabric will be caused to become bowed intermediate adjacent lines of stitches and thereby effect a roll to the lapel of a coat front.

It is of course to be understood that the details of structure and arrangements of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim 1. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming surfaces of different radii arranged in tandem, and means for adjusting said ridge forming element about the longitudinal axis of the shaft to vary the effective height of said element.

2. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming surfaces of different radii arranged in tandem, and means for oscillating said shaft including a radially adjustable connection with the shaft to vary the effective height of said element.

3. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming concentric surfaces of different radii arranged in tandem, and means for adjusting said ridge forming element about the longitudinal axis of the shaft to vary the effective height of said element.

4. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming concentric surfaces of different radii arranged in tandem, and means for oscillating said shaft including a radially adjustable connection with the shaft to vary the effective height of said element.

5. In a sewing machine, the combination in tandem, a stitch formin mechanism lowith an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming surfaces of different radii arranged in tandem, and means for oscillating said shaft including a rotary shaft, a sleeve journaled on the oscillatory shaft and having a rock arm, driving connections between the rock arm and the rotary shaft, and means fixed 'to said oscillatory shaft for fixed operative connection with the sleeve at different radial points'thereof to thereby rock the shaft and vary the effective height of said ridge forming element.

6. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixedto said shaft and having ridge forming surfaces of different radii arranged -in tandem, and means for oscillating said shaft including a rotary shaft, a sleeve journaled on the oscillatory shaft and having a rock arm and a peripheral flange, the latter having a concentric outer surface and having a plurality of seats arranged in tandem and merging with said surface, an arm fixed to the oscillatory shaft, and a radially movable latch element supported on said arm for engagement in either of said seats to thereby rock the shaft and vary the effective height of the ridge forming element- 7. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming surfaces of different radii arranged in tandem, and means for oscillating said shaft including a rotary shaft, a sleeve journaled on the oscillatory shaft and having a rock arm and a peripheral flange, the latter having a concentric outer surface and having a plurality of seats arranged in tandem and merging with said surface, abarrel fixed to said oscillatory shaft and having its longitudinal axis projecting radially thereof, and a spring pin mounted in said barrel for engagement in either of said seats to thereby rock the shaft and vary the effective height of the ridge forming element.

8. In asewing machine, the combination with an oscillatory shaft. of a ridge forming element fixed to said shaft and having ridge forming surfaces of different radii arranged cated above said element an including a re- .ciprocatory needle having a fixed path of 5 movement across the element and directly above said shaft, and means for adjusting said element about the longitudinal axis of the shaft to vary the efl'ective distance between the ele'ment and the path of needle movement.

9. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge I forming surfaces of different radii arranged in tandem, a stitch forming mechanism lo- -cated above said element and including a reciprocatory needle having a fixed path of movement across the element and directly above said shaft, and means for oscillating said shaft including a radially adjustable connection with the shaft to vary the effective distance between the element and the path of needle movement.

10. In a sewing machine, the combination with an oscillatory shaft, of a ridge forming element fixed to said shaft and having ridge forming concentric surfaces of diflerent radii arranged in tandem, the radius of the rear surface being less than. the radius of the front surface, and means for adjusting said ridge forming element about the longitudinal axis of the, shaft to vary the effective height of said element.

11. In a blind stitch sewing machine, the

combination with a stationary presser foot its center located in the general plane of the ridge forming device and in a horizontal plane below the lower surface of the foot.

12. In a blind stitch sewing machine, the

combination with a stationary presser foot having a longitudinal opening formed there on, a ridge forming device projecting into theopening, a work clamp cooperating with the under side of the foot on one side of the opening, and a projection depending from the foot and disposed along the other side of the opening and cooperating with the work clamp to clamp material therebetweemthe longitudinal walls of the opening and the 00- operating faces of the depending plate and work clamp being curvedon an arc having its center located in the general plane'of the ridge forming device and in a horizontal plane below the lower surface of the foot.

In testimony whereof I aflix my signature.

CHARLES W. MUELLER. 

